JP2667257B2 - Polyamide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polyamide resin composition having excellent heat resistance. More specifically, the present invention relates to a polyamide resin molded article used in a high-temperature environment and a heat-resistant polyamide resin composition for connectors having an excellent rust-preventing effect on metal materials coexisting therewith.

<Prior Art> Polyamide resins are used in various fields such as automobile parts and machine parts by utilizing their good mechanical properties, moldability and chemical resistance. Of these, electrical and electronic components used in the automotive field often have a high temperature environment, such as a connector in an engine room, and are required to have heat resistance.

It is known to add copper halide and potassium halide for the purpose of improving the heat resistance of polyamide resin (for example, JP-A-49-53944, JP-A-50-148461, JP-A-56-4651). issue). It is also known to add a hindered phenol compound or an imidazole compound (for example, JP-A-50-87447, JP-A-54-33559, JP-A-53-88857, JP-A-49-87857). 53944). It is also known to add an imidazole compound for another purpose (for example, JP-A-51-136797, JP-A-52-32046).

<Problems to be solved by the invention> However, conventional heat-resistant polyamide resins to which copper halide and potassium halide are added are used for electric and
When used as a connector material, which is one of the electronic components, when the use environment is at a high temperature, the metal material used in combination with the connector, particularly copper and copper alloy connection terminals, is corrosive generated from polyamide resin. It has been clarified that the gas is corroded, causing not only poor contact, but also significantly shortening the life of the terminal. At present, as electronic control devices have been highly developed, erroneous indications and malfunctions due to poor contact are extremely important issues in terms of safety in automotive applications.

Thus, the present inventors have conducted intensive studies to obtain a heat-resistant polyamide resin which has excellent heat stability and does not corrode metal materials, particularly copper and copper alloys, even under use conditions under a high-temperature environment. The present inventors have found that the above objects can be achieved by adding an organic compound in combination with copper iodide and an alkali halide, and have reached the present invention.

<Means for Solving the Problems> That is, according to the present invention, (a) 0.001 to 1 part by weight of copper iodide, (b) 0.01 to 5 parts by weight of potassium iodide and (c) General formula (I)
0.005 to 5 of the imidazole compound selected from (VIII)
An object of the present invention is to provide a polyamide resin composition for a connector which is contained by weight.

[In the formulas (I) to (VIII), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ ,
R ₈ is a hydrogen atom, a phenyl group, a benzyl group, an alkyl group,
A nitro group, a vinyl group, a tolyl group, an amino group, a carboxyl group (excluding N substitution), a hydroxyl group, an alkoxy group, an aryl group, a phenoxy group, an alkylamino group, and a halogen, R ₁ , R ₂ , and R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ may be the same group or different groups.

Other groups except for a hydrogen atom may be substituted by another group. The polyamide used in the present invention is a polyamide containing amino acids, lactams or diamines and dicarboxylic acids as main components. To give specific examples of the constituent components, ε-
Lactams such as caprolactam, enantholactam, ω-laurolactam, amino acids such as ε-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid,
Tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,
2,4- / 2,4,4-trimethylhexamethylenediamine, 5
-Methylnonamethylenediamine, m-xylylenediamine, p-xylylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, bis-p-aminocyclohexylmethane, bis-p
-Diamines such as aminocyclohexylpropane and isophoronediamine, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane diacid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and naphthalene Dicarboxylic acid,
There are dicarboxylic acids such as dimer acids. These constituents are subjected to the polymerization alone or in the form of a mixture of two or more, and any of the resulting poamide homopolymers and copolymers can be used in the present invention. Particularly useful polyamides useful in the present invention are polycapramide (nylon 6), polyhexamethylene adipamide (nylon 66),
Polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyundecaneamide (nylon 11), polydodecaneamide (nylon 12), polyhexamethylene adipamide / hexamethylene terephthalamide Polymer (nylon 66 / 6T), polycapramide / polyhexamethylene adipamide copolymer (nylon 6/66) and mixtures of these polyamides.

The degree of polymerization of the polyamide used here is not particularly limited, and the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C.
Those in the range of 1.5 to 5.0 can be arbitrarily used. The terminal group concentration of the polyamide resin is controlled by adding one or more of a monocarboxylic acid compound and / or a dicarboxylic acid compound or a monoamine compound and / or a diamine compound to the polyamide at an arbitrary stage. Is also good.

The amount of copper iodide used in the present invention is 0.001 to 1 part by weight, preferably 0.005 part by weight, per 100 parts by weight of the polyamide resin.
0.5 parts by weight. When the addition amount is less than 0.001 part by weight, the heat resistance effect becomes insufficient, which is not preferable. When the addition amount is more than 1 part by weight, the heat resistance of the obtained polyamide resin composition is not further improved.

The addition amount of potassium iodide is 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight. If the addition amount is less than 0.01 part by weight, the heat resistance effect due to the synergistic effect with copper iodide is insufficient, which is not preferable, and even if the addition amount is more than 5 parts by weight, the heat resistance of the obtained polyamide resin composition is insufficient. There is no improvement.

Examples of the imidazole compounds represented by the general formulas (I) to (VIII) used in the present invention include imidazole,
1-methylimidazole, 1-phenylimidazole,
1-benzylimidazole, 2-methylimidazole,
2-phenylimidazole, 4 (5) -phenylimidazole, 1,2-dimethylimidazole, 1,4-dimethylimidazole, 1,5-dimethylimidazole, 2,4 (2,5)
-Dimethylimidazole, 4,5-dimethylimidazole, 1,2,5-trimethylimidazole, 1,4,5-trimethylimidazole, 2,4,5-trimethylimidazole, 1
-Ethyl-2-methylimidazole, 4 (5) -methyl-2-phenylimidazole, 2,4 (2,5) diphenylimidazole, 4,5-diphenylimidazole, 2,4,5-triphenylimidazole, 2- Bromimidazole, 2
-Bromo-4 (5) -methylimidazole, 2-bromo-4 (5) -phenylimidazole, 4 (5) -bromoimidazole, 4-bromo-1-methylimidazole,
4 (5) -bromo-2-methylimidazole, 4 (5)
-Bromo-5 (4) -methylimidazole, 2,4 (2,5)
-Dibromoimidazole, 4,5-dibromoimidazole, 4,5-dibromo-1-methylimidazole, 2,4,5-
Tribromoimidazole, 5-chloro-1-methylimidazole, 5-chloro-1-ethyl-2-methylimidazole, 5-chloro-1-ethyl-2-phenylimidazole, 5-chloro-1,2-diphenylimidazole,
2,4,5-triiodoimidazole, 4-chloromethylimidazole, 5-chloromethyl-1-methylimidazole, 5 (4) -chloromethyl-4 (5) -methylimidazole, 1-benzyl-2-chloromethylimidazole, 2-oxymethylimidazole, 4 (5) -oxymethylimidazole, 5-oxymethyl-1-methylimidazole, 5 (4) -oxymethyl-4 (5) -methylimidazole, 1- (β-oxyethyl) imidazole, 4 (5)-(β-oxyethyl) imidazole, 5
(4)-(β-oxyethyl) -4 (5) -methylimidazole, 4 (5) -nitroimidazole, 2-methyl-4 (5) -nitroimidazole, 4 (5) -methyl-
5 (4) -nitroimidazole, 4 (5) -aminoimidazole, 2-aminoimidazole, 5 (4) -amino-4 (5) -methylimidazole, 2-phenylazoimidazole, 2-methyl-4 (5) -Phenylazoimidazole, histamine, 1- (β-aminoethyl) imidazole, 2- (β-aminoethyl) imidazole, 4
(5) -Aminomethylimidazole, ethyl 1-imidazole carboxylate, ethyl 4-methyl-1-imidazole carboxylate, methyl 4 (5) -amino-5 (4) -imidazole carboxylate, 4 (5) -amino- 5 (4)-
Imidazolecarboxylic acid amide, 1-methyl-4-nitro-5-imidazolecarboxylic acid, 2-imidazolecarboxylic acid, 4 (5) -methyl-2-imidazolecarboxylic acid, 4 (5) -imidazolecarboxylic acid, 2-methyl -4 (5) -imidazole carboxylic acid, 4 (5) -methyl-5 (4) -imidazole dicarboxylic acid, 2-methyl-4,5-imidazole dicarboxylic acid, 2-ethyl-4,5-
Imidazole dicarboxylic acid, 5-amino-1-methyl-
Ethyl 4-imidazole carboxylate, 4 (5) -amino-2-phenyl-5 (4) ethyl imidazole carboxylate, 2-amino-4,5-imidazole dicarboxylic acid, 4
(5) -methyl-2-nitroamino-2-imidazoline, benzimidazole, 1-methylbenzimidazole, 1-ethylbenzimidazole, 1-vinylbenzimidazole, 1-phenylbenzimidazole, 1-
Benzylbenzimidazole, 2-methylbenzimidazole, 2-ethylbenzimidazole, 2-vinylbenzimidazole, 2-phenylbenzimidazole,
2-benzylbenzimidazole, 1,2-dimethylbenzimidazole, 2-benzyl-1-methylbenzimidazole, 5,6-dimethylbenzimidazole, 2-aminobenzimidazole, 2-aminomethylbenzimidazole, 2-diethylbenzimidazole , 2- (β
-Aminoethyl) benzimidazole, 2-anilinobenzimidazole, 4 (7) -aminobenzimidazole, 5 (6) -aminobenzimidazole, 5 (6)-
Amino-2-methylbenzimidazole, 4 (7) -amino-2-methylbenzimidazole, 5,6-diaminobenzimidazole, 2-guanidinobenzimidazole, 2- (o-aminophenyl) benzimidazole,
2-benzimidazolecarboxylic acid, 1-methylbenzimidazole-2-carboxylic acid, 5 (6) -methyl-2
-Benzimidazole carboxylic acid, 4 (7) -benzimidazole carboxylic acid, 5 (6) -benzimidazole carboxylic acid, 2-methyl-5 (6) -benzimidazole carboxylic acid, 2,5 (2,6) -benzo Imidazole dicarboxylic acid, 4,5 (6,7) -benzimidazole dicarboxylic acid, 2-benzimidazolylacetic acid, β- (2-benzimidazolyl) alanine, β- (2-benzimidazolyl) propionic acid, histidine, carnosine, anserine, 2- , 3-, 4-imidazoline, 2-methyl-2-
Imidazoline, 2-phenyl-2-imidazoline, 2-
Benzyl-2-imidazoline, 1,2-diphenyl-2-
Imidazoline, 2,4,5-triphenyl-2-imidazoline, 2-chloromethyl-2-imidazoline, 2-oxymethyl-2-imidazoline, 2-nitroamino-2-imidazoline, imidazolidin, 1,3-dibenzyl- 2-
Phenylimidazoline, 1,3-dibenzylimidazoline, 1,3-dibenzyl-2-methylimidazoline, 1,3-
Dibenzyl-2-ethylimidazoline, 1,3-dipendyl-2- (p-tolyl) imidazoline, 1,3-dibenzyl-2- (p-nitrophenyl) imidazoline, 2,4,4
Imidazole compounds such as -trimethyl-1-phenylimidazoline are preferably used. More preferably, a derivative of benzimidazole is used. These imidazole compounds may be used alone or as a mixture of two or more. The amount of imidazole compound added is 0.
005 to 5 parts by weight, preferably 0.05 to 3 parts by weight. If the addition amount is less than 0.005 parts by weight, the rust-preventing effect of the metal material, particularly copper and copper alloy becomes insufficient, which is not preferable. There is no such thing.

The copper iodide, potassium iodide and imidazole compounds of the present invention can be added to the polyamide resin as it is. Further, copper iodide can be added after forming a complex salt with the imidazole compound in advance, and a complex salt of copper iodide and the imidazole compound can be used in combination with the imidazole compound used for forming the complex salt and other imidazole compounds. The addition of another heat-resistant agent (for example, a phenol derivative) is included in a preferred embodiment of the present invention.

The timing of adding the copper iodide, the alkali halide and the imidazole compound is not particularly limited. That is, it can be added at any time before, during, or after the polymerization. As the addition method after the polymerization, dry blending and melt kneading by an extruder can be effectively used.

Each additive may be added at an arbitrary stage at the same time, or may be added separately at an arbitrary stage.

Further, the polyamide resin composition of the present invention, other additives to the extent that the effect of the present invention is not significantly impaired, namely, a lubricant, an antistatic agent, a coloring agent, a crystal nucleating agent, a filler, a reinforcing material,
An appropriate amount of a heat-resistant agent, a light-resistant agent and the like can be added at any stage.

<Examples> Next, the present invention will be described in detail with reference to examples and comparative examples.

Comparative Example 1 100 parts by weight of hexamethylenediamine adipate,
Water 25 parts by weight, copper iodide 0.03 parts by weight, potassium iodide 0.5
The mixture consisting of parts by weight was put into a polymerization vessel, and after purging with nitrogen, polymerization was carried out according to a usual polymerization method. The mixture was spun into a strand from the polymerization vessel and cut with a cutter to obtain a pellet-shaped polyamide resin composition. The pellet was vacuum dried at 80 to 100 ° C. for 16 hours or more. 20 g of the dried pellets were placed in a 50 ml stoppered Erlenmeyer flask, and a copper plate and a brass plate whose surfaces were degreased were placed on the pellets and sealed. The Erlenmeyer flask was placed in a gear oven controlled at 150 ° C., heated for 300 hours continuously, taken out, and compared with the untreated copper plate and brass plate to obtain the results shown in Table 1.

Example 1 0.1 parts by weight of benzimidazole was further added to the composition of Comparative Example 1, and polymerization and evaluation were carried out in the same manner as in Comparative Example 1, and the results shown in Table 1 were obtained. The corrosiveness of copper and brass was remarkably improved as compared with the comparative example.

Example 2 Polymerization and evaluation were performed in the same manner as in Comparative Example 1 except that the amount of benzimidazole added in Example 1 was changed to 0.3 part by weight, and the results shown in Table 1 were obtained.

Examples 3 to 5 The same operation as in Comparative Example 1 except that hexamethylenediamine benzoate and adipic acid were added to the composition of Example 1 in an amount of 6 / 1,000 mol based on hexamethylenediamine adipate as a terminal group concentration regulator. The polymerization and evaluation were carried out to obtain the results shown in Table 1.

Examples 6 to 11 A mixture adjusted to the composition shown in Table 2 was put in a polymerization vessel, and polymerization and evaluation were carried out in the same manner as in Comparative Example 1 to conduct polymerization.
The results shown in the table were obtained. The corrosiveness of copper and brass was remarkably improved as compared with the comparative example, and it was found that each of these polyamide resin compositions had a high rust prevention effect.

Examples 14 to 19 The imidazole compounds shown in Table 3 were added to the polyamide resin composition obtained in Comparative Example 1 by dry blending and melt kneading, and evaluated in the same manner as in Comparative Example 1, and the results are shown in Table 3. The result was obtained.

<Effect of the Invention> The polyamide resin composition obtained by adding one or more imidazole compounds to a polyamide composition comprising a polyamide, a copper halide, and an alkali halide as in the present invention is particularly useful at a high temperature. It is possible to obtain a heat-resistant polyamide resin composition having an excellent rust-proofing effect on metal materials, particularly copper and copper alloys, which coexist with a molded article molded from the polyamide resin composition in an environment. became.

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Claims (1)

(57) [Claims] (1) 0.001 to 1 part by weight of copper iodide, (b) 0.01 to 5 parts by weight of potassium iodide, and (c) the following general formulas (I) to (VIII) based on 100 parts by weight of a polyamide resin. A polyamide resin composition for a connector, comprising 0.005 to 5 parts by weight of an imidazole compound selected from the group consisting of: [In the formulas (I) to (VIII), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ ,
R ₈ is a hydrogen atom, a phenyl group, a benzyl group, an alkyl group,
A nitro group, a vinyl group, a tolyl group, an amino group, a carboxyl group (excluding N substitution), a hydroxyl group, an alkoxy group, an aryl group, a phenoxy group, an alkylamino group, and a halogen, R ₁ , R ₂ , and R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ may be the same group or different groups. Other groups except for a hydrogen atom may be substituted by another group. ]